J:son Sweden Silicone Stonefly Nymph Legs are soft and springy and add a natural silhouette to your nymph patterns. Mark them with Chartpak or Copic markers for more realism. Chartpak AD Markers. Non-toxic silicone. Made in Sweden. Package of 12 in 2 color tones. S1 Large Size 6; S2 Medium Size 8; S3 Small Size 10; S4 X-Small Size 14; S5 Micro Size 18.